# -*- conding=utf-8 -*-
score = input("请输出你的成绩：")
score_1 = int(chenji)
if score_1 >=90 and score_1 < 100:
    print("你的级别是A")
elif score_1 >=80 and score_1 < 90:
    print("你的级别是B")
elif score_1 >= 70 and score_1 < 80:
    print("你的级别是C")
elif score_1 > 100:
    print("分数不能大于100分")
else:
    print("你的级别是D")
print("退出")